All-electric and hybrid-electric vehicles store electrical power in a storage device, such as a battery for example. The electrical power is then drawn upon by the vehicle to be converted into useful work, such as by powering motors that are connected to the vehicle's wheels. In some vehicles, such as hybrid-electric vehicles for example, the energy stored in the battery is generated by a gasoline fueled engine. The engine rotates an electrical generator that produces electrical power. The electrical power may also be generated using other means such as regenerative braking, which converts the energy dissipated during the braking and slowing down of the vehicle into electrical energy for example.
The all-electric vehicle, which lacks an independently fueled engine, relies on an external power source to provide the energy stored in the battery. The all-electric vehicle includes a receptacle that allows the operator to couple the vehicle to a utility-grid connected electrical circuit. Electrical power is transferred from the grid connected electrical circuit to the vehicle for recharging the batteries. Some all-electric vehicles may also incorporate regenerative braking features as well. A third type of vehicle, the plug-in hybrid electric (“PHEV”) includes an engine for generating power during operation, but also incorporates a receptacle to allow the operator to recharge the battery when the vehicle is not in use.
For example, FIG. 1 illustrates a typical arrangement for a conventional electric vehicle charging stand 100 for providing electricity to an electric vehicle. The conventional electric vehicle (EV) charging stand 100 includes an upright housing or stand 105 that is mounted to the ground or some other surface. The EV charging stand 100 is hard-wired to an electrical grid to receive a source of electricity to be provided to the electric vehicle. The EV charging stand 100 provides electricity to an electric vehicle through a cord 110 and a plug connector 115 that plugs into a corresponding plug receptacle on the electric vehicle.
FIG. 2 illustrates an alternative conventional arrangement for charging electric vehicles by providing a wall-mounted EV charger 200. The wall-mounted EV charger 200 is mounted to a wall or other similar surface and is typically hard wired to an electrical grid. Alternatively, the wall-mounted EV charger 200 may include a plug along the back side of the housing 205 to electrically couple the charger 200 to a source of electricity through a receptacle. The wall mounted EV charger 200 includes a housing 205 that includes electrical components for providing electricity to the electric vehicle.
In addition, similar to the EV charging stand 100, the wall-mounted EV charger 200 also includes a cord 110 electrically coupled to a plug connector 115 that plugs into a corresponding plug receptacle on the electric vehicle to provide electricity to the vehicle.
In an effort to promote standardization and interoperability, standards have been proposed, such as the J1772 standard promoted by the Society of Automotive Engineers (SAE) for example, that establish defined receptacle parameters and protocols. The J1772 standard provides three different levels of charging. The charging level depends on the capability of the vehicle to receive electrical power and the ability of the electrical circuit to deliver the power.
Level 1 charging allows the vehicle to receive electrical power from a 110 volt, 15-ampere circuit, such as that found in a common residential circuit. Level 1 charging provides an advantage in allowing the operator to connect in many locations using standard circuits, such as those commonly found in a residential garage. However, due to the low power capacity of these electrical circuits, an electric vehicle requires 24-26 hours to fully charge. A Level 2 designated charge allows the vehicle to receive electrical power from a 220V, 30 ampere circuit for example. The Level 2 charge will typically recharge a vehicle battery in three to six hours. These 220V circuits are found in some residences and may be used for certain existing appliances, such as a clothes dryer for example.
A third charging protocol, known as a Level 3 charge, provides for charging the vehicle using a 440V circuit. The charging of the vehicle on a Level 3 circuit allows the charging of the vehicle battery in two to three hours. Residences with circuits capable of Level 3 charging are not yet common and are typically only available at commercial establishments.